SpaceX Dragon (IMAGE) NASA/Johnson Space Center Caption SpaceX Dragon's third operational mission will end May 18 after a month-long stay at the International Space Station. The unmanned spacecraft will return more than 1,600 pounds of science materials from the orbital outpost. Credit NASA Usage Restrictions NASA License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.